Nosema and other diseases infect butterflies. The method to check a live butterfly for the disease nosema without harming it is to check its meconium through a microscope. Alternate methods to check for nosema require destroying the insect whether it is an egg, larva (caterpillar), pupa (chrysalis), or adult.

Emerge the butterflyand keep its meconium.

Several cups with freshMonarchs and their meconium

Meconium collected forviewing through a microscopewithout *stain

Checking meconiumthrough a microscope

This microsporida on an unstained slide resemblesgreen jelly beans

Nosema and a larger OE sporenext to a butterfly scale

Nosema spores stained withBuffalo Black Stain(c) Amanda Lawrence

Nosema spores stained withBuffalo Black Stain(c) Amanda Lawrence

We appreciate the Insect Pathologists that have taken time to share their knowledge and teach us about nosema and Vairimorpha imperfecta. Nosema is prevalent in corn borer and other moths in the US. Nosema can be passed from adult to offspring INSIDE the egg. Bleaching eggs will not kill nosema spores. Uninfected adult butterflies must be used for egg production to produce healthy butterflies.

Add stain to methanol, then add water and acetic acid. Filter before use to remove any un-dissolved stain particles. Stain can be stored at 5 degrees C (41 degrees F) for up to one month.

Allow slide to air dry.
Place the slide on a warmer heated to 40 degrees C (104 degrees F) and flood with stain.
Allow to stain for 5 minutes keeping the slide flooded, not allowing the stain to dry on the slide.
Pour the residual stain from the slide into a *waste container then gently rinse the slide in water.
Blot and then allow the slide to air dry.
Observe at 1000x using oil immersion. (We use 10x eyepiece and 100x lens.)

*MSU considers the methanol and acetic acid in the stain to be hazardous waste and therefore must be discarded and stored accordingly.